Process of dyeing coal-tar colors.



HERMANN GUTZKOW AND BENNO HOMOLKA, OF FRANKFORT-ON-THE-.

MAIN, GERMANY, ASSIGNORS TO THE FARBWERKE, VORMALS MEISTER, LUoIUs & BRUNING, OF HOCHST-ON-THE-MAIN, GERMANY.

PROCESS OF DYEING COAL-TAR COLORS.

SPECIFICATION forming part of Letters Patent No. 663,225. dated December 4, 1900.

Original application filed February 15, 1900, $eria1N'o. 5,300. Divided and this application filed September 25,1900. Serial No. 31.036. (No specimens.)

To all whom it may concern:

Be it known that We, HERMANN GUTZKOW, chemist, a citizen of the Empire of Germany, and BENNO HOMOLKA, Ph. D., a citizen of 5 the Empire of Austria-Hungary, both residing at Frankfort-on-the-Main, Germany, have invented new and useful Improvements in Producing on the Fiber Dyes Fast to Washing and Acids, of which the followingis a specification.

We have shown in our American application, Serial No. 5,300, of February 15, 1900, that a long series of coal-tar colors containing in their molecule once or more the primary or secondary amido or hydroxyl group may be transformed into new products if these colors be treated under certain conditions with such aromatic bases as contain in the molecule once or more the bivalent group -NHOI-I,or NROH (wherein R31 means alkyl) linked on both sides to benzene, (toluene or Xylene.) We have further found that by means of this peculiar chemical process remarkable shades fast to washing and acid may be obtained on the fiber, and this in such a manner that the textile fabric dyed with the above-named coal-tar colors be subsequently treated with the said aromatic bases in form of their salts soluble in water.

The practical application of our process consists in introducing the textile fabric dyed with the above specified coal-tar colors into a dilute aqueous solution of a salt of one of the above-named bases for a short time at a high temperature or for a longer time at indoor temperature till certain signs permit to judge of the completion of the reaction. The goods are then taken out of the bath, rinsed with Water, and further worked in the usual manner.

The following examples may illustrate our process:

Example I-Benzalol0let (Dolmers 'vz'olet.)(lotton dyed with benzalviolet in the usual manner is introduced into the solution of the hydrochlorid of ortho -amidometa- Xylyl-para-toluidin, thirty-two parts of the dyestufi employed being taken for fifty parts of the salt. The whole is then heated at from to till the known violet color becomes green-blue. The goods are then rinsed with water and finished in the usual manner.

Example IIEachsin.-The process here is the same as in Example I, a deep violet of great fastness to washing being obtained.

Example IIIC0ngo colors.-As Congo dyestuffs we understand here those substantive cotton dyestuffs as are obtained or supposed to be obtained by the action of tetrazodiphenyl, tetrazoditolyl and similar tetrazo compounds with two neuclei upon aromatic amins, polyamins, phenols, polyphenols, and amidophenols of the analin and naphthalene series, as well as their sulfonic and carboxylic acids.

Example l-O'ong0 red.0otton dyed in the usual manner with Congo red is introduced in a wetted state into a bath containing a solution of the hydrochlorid of monomethyl para amidobenzylalcohol obtain ed by the action of formaldehyde upon the hydrochlorid of monomethylanilin, (0.3 kilograms of the hyd rochlorid to fifteen kilograms of dyed goods.) Care must be taken for the bath to react slightly acid on Congo paper, which, if need be,is obtained by carefully adding dilute hydrochloric acid. In this bath the goods assume at once a dark-brown color. The bath is then raised to the boil and maintained at it for about thirty minutes, when the cotton assumes a brownish color. The goods are then taken out, wrung, and washed with a very dilute cold solution of sodium carbonate and finished in the usual manner. The goods are now dyed red, hardly differing in shade from the original one dyed with Congo red, yet absolutely fast to water and scarcely susceptible to dilute acetic acid. Under certain conditions the transformation of the dyestuff may also be carried out on the fiber in the bath itself after having exhausted it of the greater part ofthe dyestnff. In this case the bath is slightly acidified by the addition of hydrochloric acid. Then the hydrochlorid of the base is added and the whole is manipulated for another half-hour. The formation on the fiber of the new dyestuffs may also be effected by impregnating and steaming the previously-dyed goods with the sol ution of the hydrochlorid in question. Instead of the hydrochlorid the salts of all acids preventing the separation of the bases may be employed in this and all other cases.

Example 2-Benz0purpurm 4 B. In this case the process is the same as in the preceding example.

The goods are introduced into a solution of the hydrochlorid of the bases, obtained by the reciprocal action of molecular Y quantities of xylidin formaldehyde, and by drochloric acid. It being quite immaterial which xylidin is chosen it is best to use the technicalxylidin, being, as is known, a mixture chiefly of asmeta-Xylidin, para-Xylidin, and small quantities of other xylidins, to liftecn kilograms of cotton, 0.26 kilograms of V on adding dilute acetic acid dark brown.

I Ewaxrn JZe 3- piaminsca,1'let 3B.Tl.:1e cot,- ton goods dyed in the usual manner with diamin'scarlet 3 B are introduced into a bath containing a solution of a salt-for instance, the hydrochlorid of the above-mentioned anhydro para-amido-meta-tolylalcohol, when,

dye-bath itself. In this case the bath is acidi-- fied after the greater part of the diamin'scarlet is exhausted. Then the solution of the base is added and the formation of the dyestuft completed by boiling for half an hour. Instead of hydrochloric acid other acids preventing'the separation of the base maybe used. The formal ion of the dyestuff may also be eifected by Way of padding instead of dyeing the dyed goods With the solution of the base and subsequent steaming.

Example IV-Flu0rescem dycstufis.The process-here is the same as in the above examples. The dye obtained is considerably bluer than the original eosin-dye and surpasses the latter greatly in fastness to water and acid. The proportional weights of dyestuffs and base in the above examples must not be considered as binding and unalterable. On the contrary, they may be changed within fairly Wide limits, according to the effect desired.

We have tested, in a similar way, a, long series of coal-tar colors as to their behavior toward the bases lnentioned atthe beginning. In every case the above-cited fact was confirmed that the choice of the transforlning base is quite iminater-ial upon the result ob tainedthat is to say, the results obtained with one and the sarne dyesbuffi and difierenu bases do not diflfer much from each otherv Having now described our process, \vhat We claim 1s The herein-described process for producing on the fiber dyes fast to Washing and acids, which consists, in treating textile fabrics dyed with coal-tar colors in the usual manner,

for instance, fifteen kilograms of the dyed goods are treated with 0.2 kilograms of the said base dissolved in hydrochloric acid. The bath is then heated to from to when the goods become first dark and finally red. This being done, the goods are taken out, rinsed with Water, and finished in the usual manner. The dye thus obtained is of a vivid red, more beautiful and clearer than the original diamin-red dye, While being thoroughly fast to water and boiling acids and indifferent to acetic acid. Under these circumstances the transformation into dyestuffs fast to acid may also be carried out in the with the salts soluble in water of such aromatic bases as contain at least once the bivalent group NH-CH linked on both sides to aromatic carbon atom s, substantially as set forth.

In testimony that we claim the foregoing as our invention We have signed our names in presence of tWo subscribing Witnesses.

HERMANN GU'IZKOW. BENNO HOMOLKA.

Witnesses:

ALFRED BRISBOIS, JOHANN HARTEUSTER. 

